Parse and rebuild an URL adding new QueryString values

merge_url_query.php

<?php

function mergeUrlQuery(string $url, array $queryData = []): string
{
    $parts = parse_url($url);
    if (empty($parts['host'])) throw new \InvalidArgumentException('url');

    $originalQuery = [];
    if (!empty($parts['query'])) {
        foreach (explode('&', $parts['query']) as $i => $el) {
            list($k, $v) = explode('=', $el);
            $key = $k ? rawurldecode($k) : $i;
            $originalQuery[$key] = rawurldecode($v);
        }
    }
    $query = array_merge($originalQuery, $queryData);

    $url = ($parts['scheme'] ?? 'https') . '://';
    if (!empty($parts['user'])) $url .= $parts['user'];
    if (!empty($parts['pass'])) $url .= ':' . $parts['pass'];
    if (!empty($parts['user']) || !empty($parts['pass'])) $url .= '@';
    $url .= $parts['host'];
    if (!empty($parts['port'])) $url .= ':' . $parts['port'];
    if (!empty($parts['path'])) $url .= $parts['path'];
    $url .= '?' . http_build_query($query, '', null, PHP_QUERY_RFC3986);
    if (!empty($parts['fragment'])) $url .= '#' . $parts['fragment'];

    return $url;
}